Chapter 16
The Genitourinary System
The kidney is essential in maintaining water, salt, and
electrolyte balance and is an endocrine gland that
secretes at least three hormones. The kidney helps
control blood pressure and is especially susceptible to
damage if blood pressure is too high or too low.
Physiologic Concepts
Renal Blood Flow
The kidneys receive approximately 1 L of blood per
minute,one-fifth of the cardiac output. This high rate of
blood flow is for allowing the kidney to adjust the blood
composition continually. By adjusting the blood
composition, the kidney is able to maintain blood
volume; ensure sodium, chloride, potassium, calcium,
phosphate, and pH balance; and eliminate products of
metabolism such as urea and creatinine.
Glomerular Filtration
• The process of filtration across the glomerulus is
similar to that which occurs across all capillaries but
the glomerular capillaries have increased
permeability to small solutes and water. Also, unlike
other capillaries, the forces favoring filtration of
plasma across the glomerular capillary into
Bowman's space are greater than the forces
favoring reabsorption of fluid back into the
capillary. Therefore, net filtration of fluid into
Bowman's space occurs. This fluid then diffuses into
Bowman's capsule and begins its journey through
the rest of the nephron.
Renal Reabsorption
• Reabsorption is the second process by which the kidney
determines the concentration of a substance filtered from the
plasma. Reabsorption refers to the active (requiring energy
and always being mediated by a carrier) or the passive (no
energy required) movement of a substance filtered at the
glomerulus back into the peritubular capillaries. Reabsorption
may be total (e.g., glucose) or partial (e.g., sodium, urea,
chloride, and water).
Renal Endocrine Function
1-The kidney functions as an endocrine organ, not only with the
production and release of renin but also with the production
and release of two other hormones: 1,25-dihydroxyvitamin
D3, important for bone mineralization; and erythropoietin,
required for red blood cell production.
2- 1,25-Dihydroxyvitamin D3
The kidney acts in conjunction with the liver to produce
an active form of vitamin D, called 1,25dihydroxyvitamin D3, from an inactive precursor
consumed in the diet. The inactive form of vitamin D
can also be produced in a reaction catalyzed by sunlight
on a precursor present in the skin. Vitamin D is
essential for maintenance of plasma calcium levels
required for bone formation. The active form of vitamin
D acts as a hormone by circulating in the blood and
stimulating absorption of calcium and, to a lesser
extent, phosphate across the small intestine and across
the kidney tubules. Vitamin D also stimulates bone
resorption (breakdown). Bone resorption releases
calcium, and thus plasma calcium is increased by this
mechanism as well.
• Parathyroid hormone is the stimulus for the kidney to
play its role in activating vitamin D3. Parathyroid
hormone is released from the parathyroid gland in
response to decreased plasma calcium. This is an
example of a negative feedback cycle: decreased
plasma calcium leads to increased parathyroid
hormone, which leads to increased renal activation of
vitamin D3.
• Activation of vitamin D3 increases gut and kidney
absorption of calcium, increasing plasma calcium and
removing the stimulus for parathyroid release.
Parathyroid hormone also directly stimulates bone
resorption to release calcium into the plasma when
necessary. Individuals who have renal disease
frequently develop brittle, easily broken bones as a
result of too little active vitamin D3.
3- Erythropoietin
• The hormone that stimulates the bone marrow to
increase the production of erythrocytes (red blood
cells) is called erythropoietin. The cells of the kidney
responsible for synthesizing and releasing
erythropoietin respond to renal hypoxia. Individuals
who have renal disease frequently demonstrate
chronic and debilitating anemia.
Micturition
• Micturition is the process of urination, which is the elimination of
urine from the body. Micturition occurs when the internal and the
external urethral sphincters at the base of the bladder are relaxed.
The bladder is composed of smooth muscle (the detrusor muscle),
innervated by sensory neurons that respond to stretch, and
parasympathetic fibers that travel from the sacral area to the
bladder. An area of smooth muscle at the base of the bladder (the
internal sphincter) is also innervated by parasympathetic nerves.
An external sphincter composed of skeletal muscle is just below
the internal sphincter and at the top of the urethra. When urine
accumulates, stretch of the bladder is sensed by afferent fibers
that send the information to the spinal cord. Parasympathetic
nerves to the bladder are activated, causing contraction of the
smooth muscle and opening of the internal sphincter. At the same
time, the motor neurons going to the external sphincter are
inhibited and the external sphincter is relaxed, causing micturition
to occur.
Micturition, however, can be voluntarily inhibited. This is •
possible because at the same time that the afferent nerves
are conveying information on bladder stretch to the spinal
cord, they are also sending information up the cord to the
brainstem and cortex, allowing one to be conscious of the
need to void. Descending neurons from the brain can inhibit
or stimulate the spinal reflex to void. These descending
pathways inhibit urination by causing contraction of the
skeletal muscles of the pelvis as well as the external sphincter.
Descending pathways also block the firing of parasympathetic
nerves to the internal sphincter. For urination to be
facilitated, skeletal muscles can be voluntarily relaxed.
Voluntary control over micturition becomes functional in
children by or before the time they become 3 or 4 years of
age. However, it may become interrupted at any time by
central nervous system disease or injury or from spinal cord
trauma.
Tests of Renal Function
• Blood Urea Nitrogen
Urea is a nitrogenous waste product of protein and
amino acid metabolism. One important job of the
kidney is to eliminate this potentially toxic substance
from the body. With declining renal function, blood
urea nitrogen (BUN) levels increase. Measuring BUN
therefore provides an indication of kidney health.
BUN, however, is not only determined by renal •
function. It can also be affected by circumstances not
associated with the kidney, such as increased or
decreased dietary protein intake, or any unusual cause
of an increased protein breakdown, such as a muscle
injury. Likewise, liver disease may decrease BUN,
because the liver is necessary to convert ammonia to
urea
. Because BUN levels are affected by these other •
factors, BUN level alone may be an indiscriminate
indicator of renal disease. Therefore, often the ratio
of BUN to serum creatinine is reported as well.
Normally BUN and creatinine co-vary, keeping this
ratio at approximately 10:1. If BUN is affected by
other than renal factors, however, this ratio may
change. Ratios greater than 15:1 suggest a nonrenal cause of urea elevation. Ratios less than 10:1
occur with liver disease
Serum Creatinine
Creatinine is a product of muscle breakdown.
Creatinine is excreted by the kidney through a
combination of filtration and secretion. The
concentration of creatinine in the plasma remains
nearly constant from day to day. It varies slightly
from approximately 0.7 mg/100 mL of blood in a
small woman to 1.5 mg/l00 mL in a muscular man.
Levels greater than these suggest the kidney is not
clearing creatinine and indicate renal disease.
Serum creatinine is very indicative of renal function.
As a rough guide, a doubling of serum creatinine
levels indicates a 50% reduction in renal function.
Likewise, a tripling of normal creatinine levels
indicates a 75% reduction in renal function.
Urinalysis
A urine sample may be easily obtained and evaluated
for the presence of red blood cells, protein, glucose,
and leukocytes, all of which are normally minimal to
absent in the urine. Urine casts, which occur in the
presence of high amounts of urine protein, may also be
observed under some conditions of renal disease or
injury. Urine osmolality (specific gravity) is measurable
and should range between 1.015 and 1.025.
Dehydration causes increased urine osmolality as more
water is reabsorbed back into the peritubular
capillaries. Overhydration results in decreased urine
osmolality.
Cystoscopy
Cystoscopy is the process in which a lighted scope
(cystoscope) is inserted up the urethra into the bladder.
Bladder lesions, stones, and biopsy samples may be
taken.
Voiding Cystourethrography
Voiding cystourethrography involves bladder
catheterization and infusion of a radioactive dye to
study the shape and size of the bladder. It can be used
to detect and grade the degree of vesicoureteral reflux.
If used inappropriately, cystourethrography may spread
an unresolved bladder infection into the ureters or
kidney.
Intravenous Urography
Intravenous urography is a technique in which a
radiologic dye is injected intravenously, and x-ray
films are taken sequentially as the dye filters
through the kidney. Obstructions to flow in the
glomeruli or tubules, vesicoureteral reflux, and
stones may be visualized. A drawback to the use of
this technique is the finding that some individuals
are allergic to the dye and may suffer an
anaphylactic reaction. High doses of radiation are
involved.
Renal Ultrasound
Renal ultrasound uses the reflection of sound
waves to identify renal abnormalities, including
structural abnormalities, kidney stones, tumors,
and other masses. Because it is non-invasive and
does not involve radiation exposure, this
technique is frequently used to evaluate renal
function in children who have had a urinary tract
infection. It does not, however, offer sufficient
detail to evaluate vesicoureteral reflux, renal
scarring, or inflammation.
Pathophysiologic Concepts
Alterations in Glomerular Filtration
Glomerular filtration depends upon the summation of
forces favoring filtration of plasma out of the
glomerulus and forces favoring reabsorption of
filtrate into the glomerulus. Anything that affects
the forces of filtration or the forces of reabsorption
affects net glomerular filtration. Forces favoring
filtration are capillary pressure and interstitial fluid
colloid osmotic pressure. Forces favoring
reabsorption are interstitial fluid pressure and
plasma colloid osmotic pressure
Tubular Obstruction
One cause of increased interstitial fluid pressure is
tubular obstruction. Obstruction present in the
nephron causes fluid to back up into Bowman's
capsule and the interstitial space. Unrelieved
tubular obstruction can collapse the nephrons and
capillaries and can lead to irreversible damage,
especially to the renal papillae, which are the final
site for urine concentration. Causes of obstruction
include renal calculi (stones) and scarring from
repeated kidney infections.
Azotemia
Azotemia refers to abnormal elevation of nitrogenous waste products
in the blood such as urea, uric acid, and creatinine. Azotemia
indicates a decrease in GFR, occurring either acutely or with
chronic renal failure. Azotemia is an early sign of renal damage.
Uremia
Uremia is not a single event, but rather a syndrome (a constellation
of symptoms) that develops in an individual who has end-stage
renal disease. Because the kidney is pivotal in maintaining water,
acid-base, and electrolyte balance and in removing toxic waste
products, the symptoms of uremia are widespread and affect all
the organs and tissues of the body. Common symptoms include
fatigue, anorexia, nausea, vomiting, and lethargy. Intractable
itching (pruritus) may occur. Hypertension, osteodystrophy, and
uremic encephalopathy develop as well, with central nervous
system changes, including confusion and psychosis, characterizing
end stages.
Nephrotic Syndrome
Nephrotic syndrome is the loss of 3.5 g or more of
protein in the urine per day. Under normal
circumstances, virtually no protein is lost in the
urine. Nephrotic syndrome usually indicates severe
glomerular damage. Diabetic nephropathy is the
most common cause of nephrotic syndrome.
Clinical manifestations may include increased
susceptibility to infections (caused by
hypoimmunoglobulins) and generalized edema,
called anasarca.
Anasarca
Defined as a generalized edema in individuals
suffering from hypoalbuminemia as a result of
nephrotic syndrome or other conditions, anasarca
is caused by a systemic decrease in capillary
osmotic pressure. With a decrease in this major
force favoring reabsorption of interstitial fluid back
into the capillaries, edema of the interstitial space
throughout the body occurs. The edema is usually
soft and pitting and occurs early in the periorbital
(surrounding the eye) regions, the ankles, and the
feet.
Renal Osteodystrophy
Demineralization of bone occurring with renal
disease is known as renal osteodystrophy. Renal
osteodystrophy has many causes, including
decreased renal activation of vitamin D3, leading to
decreased calcium absorption across the gut, and
subsequent reduced serum calcium levels.
Decreased serum calcium levels also stimulate
parathyroid hormone release. An elevated bone
breakdown contributes to easy bone fracturing.
Metabolic Acidosis/Renal Acidosis
• Metabolic acidosis is a decrease in plasma pH not
caused by a respiratory disorder. Chronic renal
disease results in metabolic acidosis as a result of
reduced H+ excretion and altered bicarbonate
reabsorption. The result is increased plasma H+ and
lowered pH.
• The respiratory system is stimulated by the increase
in hydrogen. Tachypnea (increased respiratory rate)
occurs in an attempt to blow off the excess
hydrogen as carbon dioxide. The respiratory
response to renal acidosis is called respiratory
compensation.
Uremic Encephalopathy
Uremic encephalopathy refers to neurologic changes
seen in severe renal disease. Symptoms include
fatigue, drowsiness, lethargy, seizures, muscle
twitching, peripheral neuropathy (pain in the legs
and feet), decreases in memory, and coma. Uremic
encephalopathy appears to be caused by
accumulation of toxins, alterations in potassium
balance, and decreased pH.
Renal Dialysis
The process of adjusting blood levels of water and
electrolytes in a person who has poor or nonfunctioning kidneys is called renal dialysis. In this
procedure, blood is directed past an artificial
medium containing water and electrolytes in
predetermined concentrations. The artificial
medium is the dialyzing fluid. By simple diffusion
across a selectively permeable membrane, water
and electrolytes in the blood move down their
individual concentration gradients into or out of the
dialyzing solution.There are two types of dialysis:
Hemodialysis
Dialysis is performed outside the body. Blood is
passed from the body, through an arterial catheter,
into a large machine. Two chambers separated by a
semipermeable membrane are inside the machine.
Blood is delivered to one chamber, dialyzing fluid is
placed in the other, and diffusion is allowed to
occur.
It takes about 3 to 5 hours and is required
approximately three times per week. Hemodialysis
contributes to problems of anemia because some
red blood cells are destroyed in the process.
Infection is also a risk.
Peritoneal Dialysis
The individual's own peritoneal membrane is used as
a natural, semipermeable barrier. Prepared solution
(approximately 2 L) is delivered into the peritoneal
cavity. The solution is allowed to remain in the
peritoneal cavity for a predetermined amount of
time (usually between 4 and 6 hours). During this
time, water and electrolytes diffuse back and forth
between the circulating blood. The person can
usually continue activity while the exchange takes
place.
Kidney Transplantation
Kidney transplantation involves placement of a donor
kidney into the abdominal cavity of an individual
suffering from end-stage renal disease. Transplanted
kidneys can come from living or dead donors. The
more similar the antigenic properties of the donated
kidney are to the patient, the more likely the
transplantation will be successful. With appropriate
follow-up, approximately 94% of kidneys transplanted
from cadavers and 98% from living donors function
well after surgery. Long-term graft survival (10 years) is
similar for both (approximately 78% for grafts from
living donors versus 76% for grafts from cadavers).
Individuals receiving kidney donation must remain on a
variety of immunosuppressant medications for life to
prevent organ rejection. I
Conditions of Disease or Injury
Hypospadias
Hypospadias is a congenital defect in males , the
opening of the urethra is on the ventral side. This
condition may be slight or extreme. Some infants
demonstrate the urethral meatus (opening) in the
scrotal or perineal area. Ejaculatory dysfunction in
the adult male may occur.
Treatment
Surgical correction may be necessary, preferably
before the child is 1 or 2 years old. Circumcision
should be avoided in the newborn so that the
foreskin may later be used for repair.
Renal agenesis
• Failure of the kidneys to develop during gestation
,may be unilateral or bilateral. Bilateral agenesis is
incompatible with life.
• Unilateral agenesis results in hypertrophy of the
remaining kidney as it adapts to compensate
functionally for the absent kidney.
Clinical Manifestations
With unilateral renal agenesis, no symptoms are
apparent if the remaining kidney is healthy. The
remaining kidney may compensate and grow almost
twice as big as otherwise expected. If the remaining
kidney functions poorly, however, various disease
manifestations may be present.
Diagnostic Tools
• Prenatal ultrasound can often detect renal
agenesis.
• After birth, computerized axial tomography
(CAT) scan or renal ultrasound is used to
diagnose the condition.
Treatment
• No treatment is required for unilateral agenesis
if the remaining kidney is healthy.
• If structural or functional defects are present in
the remaining kidney, surgery may be required.
Renal Calculi
Renal calculi refer to stones that occur anywhere in
the urinary tract. Calculi are most commonly made
up of calcium crystals. Renal calculi can be caused
by either increased urine pH (e.g., calcium
carbonate stones) or decreased urine pH (e.g., uric
acid stones).
Anything that obstructs urine flow, leading to urine
stasis anywhere in the urinary tract, increases the
likelihood of stone formation.
Clinical Manifestations
• Pain is often colicky (rhythmic), especially if
the stone is in the ureter or below. The pain
may be intense. The location of pain depends
on the site of the stone.
• A stone in the kidney itself may be
asymptomatic unless it causes obstruction or
an infection develops.
• Hematuria, caused by irritation and injury of
the renal structures, is common with calculi.
• Decreased urine output results if obstruction
to flow occurs.
Diagnostic Tools
Radiograph, ultrasound, or intravenous urography may
locate a stone.
Complications
• Urinary obstruction can lead to hydroureter, that is,
abnormal distension of ureter with urine. Unrelieved
hydroureter can lead to hydronephritis, swelling of the
renal pelvis and collecting-duct system. leading to
electrolyte and fluid imbalance.
• Obstruction causes increased interstitial hydrostatic
pressure and can lead to a decrease in GFR. Renal
failure may develop if both kidneys are involved.
• The chance of a bacterial infection increases.
• Renal cancer may develop from repeated inflammation
and injury.
Treatment
• High fluid intake in individuals prone to calculi may
prevent their formation.
• Increased fluid intake increases urine flow and helps
wash out the stone.
• Appropriate alteration of urine pH may encourage
stone breakdown.
• Lithotripsy (shock wave therapy) or laser therapy
may be used to break apart the stone.
• Surgery may be necessary to remove a large stone
or to place a diversion tube around the stone to
relieve obstruction.
Urinary Tract Infection
A urinary tract infection is an infection anywhere in
the urinary tract, including the kidney itself.
Most urinary tract infections are bacterial in origin,
but fungi and viruses also may be implicated.
The most common bacterial infection is by
Escherichia coli, a fecal contaminant commonly
found in the anal area.
• Urinary tract infections are especially common in
girls and women. One cause is the shorter urethra
in the female, which allows the contaminating
bacteria to gain access more easily to the bladder.
• Individuals who have diabetes also are at risk of
frequent urinary tract infections because of the high
glucose content of the urine and poor immune
function.
• Persons who have a spinal cord injury or anyone
using a urinary catheter to void are at increased risk
of infection.
Types of Urinary Tract Infections
• Urinary tract infections may be divided into cystitis
and pyelonephritis. Cystitis is an infection of the
bladder, the most common site for an infection.
Pyelonephritis is an infection of the kidney itself
and can be either acute or chronic.
• Acute pyelonephritis usually occurs as a result of
an ascending bladder infection. It may also occur
as a result of a blood-borne infection. Infections
may be in both or in one kidney.
• Chronic pyelonephritis may result from repeated
infections and is usually found in individuals who
have frequent calculi, other obstructions, or
vesicoureteral reflux.With chronic pyelonephritis,
extensive scarring and obstruction of the tubules
result. The ability of the kidneys to concentrate
urine decreases as tubules are lost. The glomeruli
are usually unaffected. Chronic renal failure may
develop.
Clinical Manifestations
Cystitis typically presents with dysuria (pain on
urination), increased frequency of urination, and a
sense of urgency to urinate.
• Lower back or suprapubic pain may occur, especially
with pyleonephritis.
• Fever accompanied by blood in the urine in severe
cases.
• Symptoms of infection in infants or young children
may be non-specific and include irritability, fever,
lack of appetite, vomiting, and very strong-smelling
diapers.
Acute pyelonephritis typically presents with
• Fever.
• Chills.
• Flank pain.
• Dysuria.
Chronic pyelonephritis may have manifestations
similar to acute pyelonephritis. However, it
can also include hypertension and may
eventually lead to signs of renal failure.
Diagnostic Tools
• Urine culture and sensitivity of the microorganism
allow for identification and treatment.
• White blood cells will be present in the urine with
infection anywhere. White cell casts present in the
urine suggest pyleonephritis rather than cystitis,
since they indicate that white cells have been lysed
in the tubules.
Complications
• Renal or perirenal abscess formation may occur.
• Renal failure may develop after repeated infections
if both kidneys are involved.
• Treatment
• Women and girls in particular should be encouraged to
drink fluids frequently.
• Girls should be taught at a young age to wipe from
front to back after urination to avoid contamination of
the urethral opening with fecal bacteria.
• Women should be encouraged to urinate after sexual
intercourse to wash out ascending microorganisms.
• Antibiotic therapy with to repeat urinalysis during or
after drug therapy is required.
• If chronic pyelonephritis is caused by an obstruction or
reflux, surgical treatment specific to relieve these
problems is necessary.
Glomerulonephritis
Glomerulonephritis is an inflammation of the
glomerulus. Types of glomerulonephritis include :
I-Acute Glomerulonephritis
occurs as a result of deposition of antibody-antigen
complexes in the glomerular capillaries. Complexes
usually develop 7 to 10 days after a pharyngeal or
skin streptococcal infection (poststreptococcal
glomerulonephritis) but may follow any infection.
An inflammatory reaction is initiated in the
glomerulus after deposition of antibody-antigen
complexes.
It usually resolves with specific antibiotic therapy,
especially in children.
II-Rapidly Progressive Glomerulonephritis
Is an inflammation of the glomeruli that occurs so
rapidly that there is a 50% decrease in GFR within 3
months of disease onset. Rapidly progressive
glomerulonephritis can occur from a worsening of
acute glomerulonephritis, from an autoimmune
disease, or may be idiopathic (unknown) in origin.
III-Chronic Glomerulonephritis
Is the long-term inflammation of the glomerular
cells. It may occur as a result of unresolved acute
glomerulonephritis, or it might develop
spontaneously. It commonly occurs after years of
subclinical glomerular injury and inflammation,
associated with only slight hematuria and
proteinuria.
Clinical Manifestations
All types of glomerulonephritis are associated with:
• Decreased urine volume.
• Blood in the urine (brownish-colored urine).
• Fluid retention.
Diagnostic Tools
• Hematuria as measured by urinalysis.
• Red blood cell casts in the urine.
• Proteinuria greater than 3 to 5 g/day.
• Decreased GFR as measured by creatinine
clearance.
• In poststreptococcal glomerulonephritis,
antistreptococcal enzymes, such as antistreptolysinO and antistreptokinase, will be present.
Complications
• Renal failure may develop.
Treatment
• If the condition develops following acute
poststreptococcal glomerulonephritis, antibiotic
therapy is required.
• Autoimmune destruction of the glomeruli may be
treated with corticosteroids for
immunosuppression.
• Anticoagulants to decrease fibrin deposits and
scarring can be used in rapidly progressive
glomerulonephritis.
• Strict glucose control in diabetics has been shown
to slow or reverse the progression of
glomerulonephritis.
•
Renal Failure
Renal failure is the loss of function in both kidneys.
The stages of kidney disease are as follows:
• Stage 1: abnormalities in blood or urine tests with
normal or near-normal glomerular filtration rate .
Stage 2: Glomerular filtration rate approximately
50% of normal, with evidence of kidney damage.
• Stage 3: Glomerular filtration rate between 25 to
50% of normal.
• Stage 4: Glomerular filtration rate between 12 to
24% of normal, .
• Stage 5: End-stage renal failure; glomerular
filtration rate of less than 12% of normal
• Renal failure also is categorized as acute or chronic
renal failure
Acute Renal Failure
Causes of acute renal failure have been separated
into three general categories: prerenal, intrarenal,
and postrenal.
• Prerenal failure occurs as a result of conditions
unrelated to the kidney but that damage the kidney
by affecting renal blood flow. Causes of prerenal
failure include myocardial infarct, an anaphylactic
reaction, severe blood loss or volume depletion, a
burn, or sepsis (a blood-borne infection).
• Intrarenal failure ,result from primary damage to
kidney tissue itself. It has many causes, including
glomerulonephritis and acute pyelonephritis, .
• Postrenal failure result from conditions that affect
the flow of urine out of the kidneys and includes
injury to or disease of the ureters , bladder, or
urethra. The usual cause of postrenal failure is
obstruction.
Clinical Manifestations
• Oliguria results from decreased GFR.
Diagnostic Tools
• Azotemia (increased nitrogenous compounds in the
blood).
• elevated BUN and creatinine.
• hyperkalemia (increased potassium in the blood)
and acidosis are common.
Complications
• Fluid retention may lead to edema, congestive
heart failure, or water intoxication.
• Alterations in electrolytes and pH may cause uremic
encephalopathy.
• If the hyperkalemia is severe ( 6.5 mEq/L),
dysrhythmia and muscle weakness may occur.
Treatment
- Prevention of acute renal failure is essential.
- Individuals experiencing shock should be quickly treated with
fluid replacement to support blood pressure.
- Prevention of oliguria .
Chronic Renal Failure
Is the progressive destruction of renal structure.
Clinical Manifestations
• In stage 1 renal failure, no symptoms may be apparent.
• As disease progresses, reduced production of erythropoietin
causes chronic fatigue, and early signs of tissue hypoxia .
• As disease progresses, polyuria (increased urine output)
occurs as the kidneys are unable to concentrate the urine.
• During the final stages of renal failure, urine output decreases
because of low GFR.
Diagnostic Tools
• Radiographs or ultrasound .
• Serum BUN, creatinine, and GFR will be abnormal.
• Hematocrit and hemoglobin are reduced.
• Plasma pH is low.
• An elevated respiratory rate indicates respiratory
compensation for metabolic acidosis.
Complications
• With progression of renal failure, volume overload,
electrolyte imbalance, metabolic acidosis, azotemia,
and uremia occur.
• In stage 5 renal failure (end-stage disease), severe
azotemia and uremia are present. Metabolic acidosis
worsens, which significantly stimulates respiratory rate.
• Hypertension, anemia, hyperkalemia, uremic
encephalopathy, and pruritus (itching) are common
complications.
• Decreased production of erythropoietin may lead to
anemia .
• Congestive heart failure may develop.
• Without treatment, coma and death result.
Treatment
• Prevention of renal failure is the most important
goal. Prevention includes lifestyle changes and
drugs when necessary to control hypertension,
good glycemic control in diabetics, and the
avoidance of nephrotoxic drugs whenever possible.
Childhood Kidney Cancer: Wilms' Tumor
Wilms' tumor is a cancer of the kidney that typically
develops in children younger than 4 years of age.
It can grow to a large size. It may be encapsulated
(contained within the capsule of the kidney).
-Encapsulation is associated with a favorable prognosis,
whereas spread of the tumor outside of the abdominal
area to the lungs is associated with a poorer outcome.
-Overall, prognosis is good, with an approximately 90%
survival rate.
Clinical Manifestations
• A large abdominal mass may be noted by parents or a
health-care provider.
• Vomiting, abdominal pain, and hematuria may be
present.
Diagnostic Tools
• A careful history can raise suspicion of Wilms'
tumor.
• Physical examination may identify the mass.
• CT scan or ultrasound may confirm the
diagnosis.
Treatment
• Chemotherapy and surgery are used
aggressively to destroy the tumor.
•
•
•
•
Adult kidney cancer
This cancer is especially common in the sixth or
seventh decade of life, and is more common in
males than in females.
Risk factors include repeated kidney stone
irritation, smoking, and obesity.
Symptoms include hematuria and the presence of a
flank mass.
Treatment and outcomes depend on staging, with
outcomes ranging from 85% survival for stage I
tumors to less than 10% survival for stage IV
tumors.
Clinical Manifestations
• Hematuria is the most common manifestation.
It may be frankly visible or may be microscopic
and sporadic.
• A flank mass may be palpable. Flank pain may
be present as well.
• Polycythemia may be present, reflecting
alteration in the renal control of
hematopoiesis.
• Fever may accompany the cancer.
Diagnostic Tools
• CT scanning .
• Ultrasound, renal angiography, and MRI may
confirm the diagnosis.
• Complications
• Metastasis to the lungs or elsewhere may precede
diagnosis.
Treatment
• Surgery.
• Chemotherapy and immunotherapy may be used as
well.